Use of Gibberellic Acid to Increase the Salt Tolerance of Leaf Lettuce and Rocket Grown in a Floating System

Hydroponics need water of good quality to prepare a balanced nutrient solution that could allow plants to reach their maximum yield potential. The rising difficulties in finding water with good quality have led to the compelling necessity of identifying sustainable ways to use saline water, limiting its negative effect on crop yield and quality. The exogenous supplementation of plant growth regulators, such as gibberellic acid (GA3), can be effective in increasing plant growth and vigor, thus helping plants to better cope with salt stress. The aim of this study was to evaluate the feasibility to increase the salt tolerance of leaf lettuce and rocket grown in a floating system by adding GA3 (10−6 M) to mineral nutrient solutions (MNS) with increasing salinity (0, 10, and 20 mM NaCl). Leaf lettuce and rocket plants suffered a significant reduction of growth and yield, determined by the reduction of biomass, leaf number, and leaf area, even with moderate salt stress (10 mM NaCl). The supplementation of exogenous GA3 through the MNS allowed plants to substantially counterbalance salt stress by enhancing various morphological and physiological traits, such as biomass accumulation, leaf expansion, stomatal conductance and water and nitrogen use efficiency. The effects of salt stress and GA3 treatment varied according to the species, thus indicating that this interaction may improve salt tolerance by activating different adaptation systems.

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Alleviation of Salt Stress by Plant Growth-Promoting Bacteria in Hydroponic Leaf Lettuce

Agronomy ◽

10.3390/agronomy10101523 ◽

2020 ◽

Vol 10 (10) ◽

pp. 1523 ◽

Cited By ~ 1

Author(s):

Alessandra Moncada ◽

Filippo Vetrano ◽

Alessandro Miceli

Keyword(s):

Salt Stress ◽

Plant Growth ◽

Leafy Vegetables ◽

Mineral Nutrient ◽

Plant Growth Promoting Bacteria ◽

Plant Growth Promoting ◽

Growth Promoting ◽

Leaf Lettuce ◽

Positive Effect ◽

Nutrient Solutions

Mediterranean areas with intensive agriculture are characterized by high salinity of groundwater. The use of this water in hydroponic cultivations can lead to nutrient solutions with an electrical conductivity that overcomes the tolerance threshold of many vegetable species. Plant growth-promoting rhizobacteria (PGPR) were shown to minimize salt stress on several vegetable crops but the studies on the application of PGPR on leafy vegetables grown in hydroponics are rather limited and have not been used under salt stress conditions. This study aimed to evaluate the use of plant growth-promoting bacteria to increase the salt tolerance of leaf lettuce grown in autumn and spring in a floating system, by adding a bacterial biostimulant (1.5 g L−1 of TNC BactorrS13 a commercial biostimulant containing 1.3 × 108 CFU g−1 of Bacillus spp.) to mineral nutrient solutions (MNS) with two salinity levels (0 and 20 mM NaCl). Leaf lettuce plants showed a significant reduction of growth and yield under salt stress, determined by the reduction of biomass, leaf number, and leaf area. Plants showed to be more tolerant to salinity in autumn than in spring. The inhibition of lettuce plant growth due to salt stress was significantly alleviated by the addition of the bacterial biostimulant to the MNS, which had a positive effect on plant growth and fresh and dry biomass accumulation of the unstressed lettuce in both cultivation seasons, and maintained this positive effect in brackish MNS, with similar or even significantly higher values of morphologic, physiologic, and yield parameters than those recorded in control unstressed plants.

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Effect of Gibberellic Acid on Growth, Yield, and Quality of Leaf Lettuce and Rocket Grown in a Floating System

Agronomy ◽

10.3390/agronomy9070382 ◽

2019 ◽

Vol 9 (7) ◽

pp. 382 ◽

Cited By ~ 19

Author(s):

Alessandro Miceli ◽

Alessandra Moncada ◽

Leo Sabatino ◽

Filippo Vetrano

Keyword(s):

Gibberellic Acid ◽

Nutrient Solution ◽

Production Systems ◽

Growth Yield ◽

Mineral Nutrient ◽

Yield And Quality ◽

Floating System ◽

Use Efficiency ◽

Leaf Lettuce

Gibberellins (GAs) are growth hormones strongly involved in a wide variety of physiological activities. Currently, gibberellins are commercially used to enhance phenotypic characteristics, earliness, and productivity of many vegetable and ornamental crops. In this work, the efficacy of supplementation of low levels of gibberellic acid (0, 10−8, 10−6, and 10−4 M GA3) through the mineral nutrient solution of a floating system on yield and quality of leaf lettuce and rocket plants was tested. The marketability of plants was lost when 10−4 M GA3 was added to the mineral nutrient solution. This study demonstrated that the addition of 10−4 M GA3 exceeded the acceptable threshold for use in hydroponics production systems. Below the concentration of 10−4 M, the presence of GA3 in the mineral nutrient solutions (MNS), especially at 10−6 M GA3, stimulated plant growth and enhanced the yield. Various morphological and physiological traits were enhanced by GA3 treatments (biomass accumulation, leaf expansion, stomatal conductance, water use efficiency (WUE), Nitrogen use efficiency (NUE), etc.), with superimposable trends in both lettuce and rocket. The addition of 10−6 M GA3 to the nutrient solution of a hydroponic floating system can promote growth and quality of lettuce and rocket plants.

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Rhizobacteria containing ACC-deaminase confer salt tolerance in maize grown on salt-affected fields

Canadian Journal of Microbiology ◽

10.1139/w09-092 ◽

2009 ◽

Vol 55 (11) ◽

pp. 1302-1309 ◽

Cited By ~ 104

Author(s):

Sajid Mahmood Nadeem ◽

Zahir Ahmad Zahir ◽

Muhammad Naveed ◽

Muhammad Arshad

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Plant Growth ◽

Ethylene Production ◽

Acc Deaminase ◽

Plant Growth Promoting Rhizobacteria ◽

Growth And Yield ◽

Negative Effect ◽

Plant Growth Promoting ◽

Growth Promoting

Salt stress is one of the major constraints hampering agricultural production owing to its impact on ethylene production and nutritional imbalance. A check on the accelerated ethylene production in plants could be helpful in minimizing the negative effect of salt stress on plant growth and development. Four Pseudomonas , 1 Flavobacterium , and 1 Enterobacter strain of plant growth promoting rhizobacteria containing 1-aminocyclopropane-1-carboxylate (ACC)-deaminase were selected and their effects on growth and yield of maize were investigated to improve the salt tolerance of maize grown on salt-affected fields. The selected rhizobacterial isolates reduced or eliminated the classical “triple” response, indicating their ability to reduce stress-induced ethylene levels. Results showed that rhizobacterial strains, particularly Pseudomonas and Enterobacter spp., significantly promoted the growth and yield of maize compared with the non-inoculated control. Pseudomonas fluorescens increased plant height, biomass, cob yield, grain yield, 1000 grain mass, and straw yield of maize up to 29%, 127%, 67%, 60%, 17%, and 166%, respectively, over the control. Under stress conditions, more N, P, and K uptake and high K+–Na+ ratios were recorded in inoculated plants compared with the control. The results imply that inoculation with plant growth promoting rhizobacteria containing ACC-deaminase could be a useful approach for improving growth and yield of maize under salt-stressed conditions.

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An ABA Functional Analogue B2 Enhanced Salt Tolerance by Inducing the Root Elongation and Reducing Peroxidation Damage in Maize Seedlings

International Journal of Molecular Sciences ◽

10.3390/ijms222312986 ◽

2021 ◽

Vol 22 (23) ◽

pp. 12986

Author(s):

Shiying Geng ◽

Zhaobin Ren ◽

Lijun Liang ◽

Yumei Zhang ◽

Zhaohu Li ◽

...

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Plant Growth ◽

Growth Regulator ◽

Plant Growth Regulator ◽

Growth And Yield ◽

The Novel ◽

Root Shoot Ratio ◽

Maize Leaves ◽

Hydroponic Conditions

Salt stress negatively affects maize growth and yield. Application of plant growth regulator is an effective way to improve crop salt tolerance, therefore reducing yield loss by salt stress. Here, we used a novel plant growth regulator B2, which is a functional analogue of ABA. With the aim to determine whether B2 alleviates salt stress on maize, we studied its function under hydroponic conditions. When the second leaf was fully developed, it was pretreated with 100 µM ABA, 0.01 µM B2, 0.1 µM B2, and 1 µM B2, independently. After 5 days treatment, NaCl was added into the nutrient solution for salt stress. Our results showed that B2 could enhance salt tolerance in maize, especially when the concentration was 1.0 µMol·L−1. Exogenous application of B2 significantly enhanced root growth, and the root/shoot ratio increased by 7.6% after 6 days treatment under salt stress. Compared with control, the ABA level also decreased by 31% after 6 days, which might have resulted in the root development. What is more, B2 maintained higher photosynthetic capacity in maize leaves under salt stress conditions and increased the activity of antioxidant enzymes and decreased the generation rate of reactive oxygen species by 16.48%. On the other hand, B2 can enhance its water absorption ability by increasing the expression of aquaporin genes ZmPIP1-1 and ZmPIP1-5. In conclusion, the novel plant growth regulator B2 can effectively improve the salt tolerance in maize.

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Influence of Preharvest Gibberellic Acid Treatments on Postharvest Quality of Minimally Processed Leaf Lettuce and Rocket

Horticulturae ◽

10.3390/horticulturae5030063 ◽

2019 ◽

Vol 5 (3) ◽

pp. 63 ◽

Cited By ~ 8

Author(s):

Alessandro Miceli ◽

Filippo Vetrano ◽

Leo Sabatino ◽

Fabio D’Anna ◽

Alessandra Moncada

Keyword(s):

Gibberellic Acid ◽

Cold Storage ◽

Postharvest Quality ◽

Mineral Nutrient ◽

Nitrate Content ◽

Minimally Processed ◽

Positive Effects ◽

Floating System ◽

Leaf Lettuce ◽

Nutrient Solutions

Plant growth regulators are used in high-value vegetable crops during cultivation and after harvest to increase yield, enhance crop management, and improve or retain the produce quality. The aim of this work was to evaluate the quality characteristics during cold storage of minimally processed leaf lettuce and rocket, obtained from plants grown in a hydroponic floating system with mineral nutrient solutions (MNS) containing different levels of gibberellic acid (GA3). Plants were grown in greenhouse conditions on nutrient solutions containing 0, 10−8, and 10−6 M GA3. At harvest, lettuce and rocket were immediately processed as fresh-cut vegetables and stored for 21 d at 4 °C. After processing, weight loss, total soluble solids, titratable acidity, ascorbic acid and nitrate content, leaf color characteristics, and overall quality were evaluated. Adding 10−6 M GA3 to the MNS of a floating system significantly increased the yield of leaf lettuce and rocket plants and of minimally-processed leaves. In addition, preharvest GA3 treatments had positive effects on delaying senescence and enhancing shelf-life of minimally processed lettuce and rocket. The slowed senescence of GA3-treated samples maintained an overall quality over the threshold of marketability in both lettuce and rocket for up to 21 d of cold storage.

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Gibberellic Acid Induced Changes on Growth, Yield, Superoxide Dismutase, Catalase and Peroxidase in Fruits of Bitter Gourd (Momordica charantia L.)

Horticulturae ◽

10.3390/horticulturae6040072 ◽

2020 ◽

Vol 6 (4) ◽

pp. 72

Author(s):

Mazhar Abbas ◽

Faisal Imran ◽

Rashid Iqbal Khan ◽

Muhammad Zafar-ul-Hye ◽

Tariq Rafique ◽

...

Keyword(s):

Plant Growth ◽

Gibberellic Acid ◽

Growth Yield ◽

Growth And Yield ◽

Bitter Gourd ◽

Antioxidant Enzyme Activities ◽

Yield And Quality ◽

Dual Action ◽

Induced Changes ◽

The Impact

Bitter gourd is one of the important cucurbits and highly liked among both farmers and consumers due to its high net return and nutritional value. However, being monoecious, it exhibits substantial variation in flower bearing pattern. Plant growth regulators (PGRs) are known to influence crop phenology while gibberellic acid (GA3) is one of the most prominent PGRs that influence cucurbits phenology. Therefore, a field trial was conducted at University of Agriculture Faisalabad to evaluate the impact of a commercial product of gibberellic acid (GA3) on growth, yield and quality attributes of two bitter gourd (Momordica charantiaL.) cultivars. We used five different concentrations (0.4 g, 0.6 g, 0.8 g, 1.0 g, and 1.2 g per litre) of commercial GA3 product (Gibberex, 10% Gibberellic acid). Results showed that a higher concentration of gibberex (1.0 and 1.20 g L−1 water) enhanced the petiole length, intermodal length, and yield of bitter gourd cultivars over control in Golu hybrid and Faisalabad Long. A significant decrease in the enzyme superoxidase dismutase, peroxidase, and catalase activities were observed with an increasing concentration of gibberex (1.0 and 1.20 gL−1 water) as compared to control. These results indicate that the exogenous application of gibberex at a higher concentration (1.2 g L−1) has a dual action in bitter gourd plant: i) it enhances the plant growth and yield, and ii) it also influenced the antioxidant enzyme activities in fruits. These findings may have a meaningful, practical use for farmers involved in agriculture and horticulture.

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Alleviation of salt stress using gibberellic acid in Chinese cabbage

Acta Agronomica Hungarica ◽

10.1556/aagr.60.2012.4.5 ◽

2012 ◽

Vol 60 (4) ◽

pp. 345-355 ◽

Cited By ~ 2

Author(s):

M. Jamil ◽

M. Ashraf ◽

E. Rha

Keyword(s):

Salt Stress ◽

Gibberellic Acid ◽

Chinese Cabbage ◽

Germination Rate ◽

Harmful Effect ◽

Seed Priming ◽

Nacl Stress ◽

Growth And Yield ◽

Distilled Water ◽

Membrane Injury

Salinity reduces plant growth and yield by affecting morphological and physiological processes. To alleviate the harmful effects of salt stress various approaches involving plant hormones are used. In this study several parameters involving the measurement of cell membrane injury were used to observe whether stress tolerance could be enhanced in Chinese cabbage (B. oleracea capitata L. Chinensis group) by soaking the seeds for 10 h in distilled water (control), or in 100, 150 or 200 mg l−1 gibberellic acid (GA3). The NaCl concentrations were 0 (control), 50, 100 and 150 mM. Seed treated with GA3 showed increased water uptake and decreased electrolyte leakage as compared to that of distilled water-primed seeds even 24 h after soaking under control conditions. Seed priming with GA3 increased the final germination and the germination rate (1/t50, where t50 is the time to 50% germination) under salt stress conditions. Seed priming also alleviated the harmful effect of salt stress on cabbage in terms of fresh and dry weights. Leaf area was higher in plants raised from seeds primed with the higher GA3 concentrations as compared with those raised from seeds treated with distilled water under control conditions (without NaCl) or at 50 mM NaCl stress. The chlorophyll content increased with the NaCl concentration, especially in plants grown from seeds primed with GA3. Plants grown from GA3-primed seeds also suffered lower cellular injury both under control conditions and under NaCl stress.

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Silicon ameliorates the adverse effects of salt stress on sainfoin (Onobrychis viciaefolia) seedlings

Plant Soil and Environment ◽

10.17221/665/2017-pse ◽

2017 ◽

Vol 63 (No. 12) ◽

pp. 545-551 ◽

Cited By ~ 1

Author(s):

Wu Guo-Qiang ◽

Liu Hai-Long ◽

Feng Rui-Jun ◽

Wang Chun-Mei ◽

Du Yong-Yong

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Adverse Effects ◽

Plant Growth ◽

Membrane Permeability ◽

Chlorophyll Content ◽

Salinity Stress ◽

Soluble Sugars ◽

Organic Solutes ◽

Relative Membrane Permeability

The objective of this study was to investigate whether the application of silicon (Si) ameliorates the detrimental effects of salinity stress on sainfoin (Onobrychis viciaefolia). Three-week-old seedlings were exposed to 0 and 100 mmol/L NaCl with or without 1 mmol/L Si for 7 days. The results showed that salinity stress significantly reduced plant growth, shoot chlorophyll content and root K+ concentration, but increased shoot malondialdehyde (MDA) concentration, relative membrane permeability (RMP) and Na+ concentrations of shoot and root in sainfoin compared to the control (no added Si and NaCl). However, the addition of Si significantly enhanced growth, chlorophyll content of shoot, K+ and soluble sugars accumulation in root, while it reduced shoot MDA concentration, RMP and Na+ accumulation of shoot and root in plants under salt stress. It is clear that silicon ameliorates the adverse effects of salt stress on sainfoin by limiting Na+ uptake and enhancing selectivity for K+, and by adjusting the levels of organic solutes. The present study provides physiological insights into understanding the roles of silicon in salt tolerance in sainfoin.

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Morpho-physiological and molecular responses of two Libyan bread wheat cultivars to plant growth regulators under salt stress

Italian Journal of Agronomy ◽

10.4081/ija.2020.1633 ◽

2020 ◽

Vol 15 (3) ◽

Author(s):

El Hadi Hadia ◽

Amor Slama ◽

Leila Romdhane ◽

Hatem Cheikh M’hamed ◽

Ahmed Houssein Abodoma ◽

...

Keyword(s):

Gene Expression ◽

Salt Stress ◽

Plant Growth ◽

Gibberellic Acid ◽

Plant Growth Regulators ◽

Bread Wheat ◽

Growth Regulators ◽

Glycine Betaine ◽

Growth Yield ◽

Wheat Varieties

To study the effects of salt stress and plant growth regulators (kinetin, gibberellic acid, potassium) on growth, yield, glycine betaine content, phosphoenolpyruvate carboxylase (PEPC) and ribulose biphosphate carboxylase (RBC) gene expression of two Libyan bread wheat varieties, a factorial design of greenhouse experiment with three replications was conducted. Results revealed that salt stress significantly reduced plant growth and productivity of both varieties. Moreover, the addition of kinetin + potassium and gibberellic acid + potassium had improved the performance of the morpho-metric parameters of both genotypes under salt stress; but the performance was more effective for kinetin treatment than for gibberellic acid. At the biochemical level, the results showed that salt stress increased glycine betaine contents in both varieties with different proportions. This increase is more elevated in the presence of kinetin + potassium than the treatment with gibberellic acid+ potassium, which showed an almost similar result as in only salt stress. At the molecular level, the effects of salt stress and plant growth regulators on the PEPC and RBC gene expression showed that the increase was significantly higher for kinetin, gibberellic acid, and salt stress when compared to the control.

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